Direct lymphovenous anastomoses were constructed in dogs with chronic obstructit on the course of the lymphedema. Early patency rates of the lymphovenous anastomoses of 100 percent related to a 32 percent decrease in the lymphedema. However, by 3 weeks, all lymphovenous anastomoses became occluded and the edema level returned to the original state or was somewhat worse. Patent lymphovenous anastomoses seem clearly capable of improving the lymphedema state. However, long-time patency was not maintained in this series. We postulate that effective decompression of the lymphedematous leg by the patent lymphovenous anastomoses results in decreased flow through the anastomoses with subsequent occlusion.